Method of burning powdered fuel.



H. R. BARNHURST. METHOD OF BRNING PWDBRBD FUEL.

APPLIGATIc-n HLBD su. 21, 1910.

961,672. Patented' Jun@ 14.1910.

ATTORNEY5 vUNITED STATES Parana. tiraron..

HENRY B. BABNHURST, OF ALLENTOWN, TPENNSYLVANIA, ASSIGOR OF ONf-HALF- TOHENRY GREGORY BARNHURST, OF CATASAUQUA, PENNSYLVANIA.

)IETHOD OF BURNING POWDEBED FUEL.

specification of Letters Fatent.

To all whom it may concern:

Be it known that l, HENRY ing at Allentown, county of `Lehigh, State ofPennsylvania. have invented certain new and useful liiiprorcinents. iiiMethods of i Burning Powdered Fuel; and I do hereby and in spite of ilvcfari that, unlike ordideclare thc followiiiT to be a full, clear, andexact description o the invention, sueh as will enable others skilled inthe art to which it a pertains to malte and use. the same.

Ally invention relates to improvements in cil'ecting the combustion, forindustrial purposes, of fuel of such a character that ordinarexpedieiits for burning it are attended with but indifferent results.

One of the materials for whose combustion the invention is particularlyintended is anthracite ciilm, thatis to say, the fine screenings andother refuse from coal mixiing operations` which have accumulated inlarge quantities in the neighborhood of coal mines and coal breakers,and including the still more finely divided anthracite mud constitutingthe tailings of coal wasbcries.

v,The smaller sizes of anthracite coal are to Aa greater or less extentrecoverable as such from tliecnliii, by various separating operations,and appear on the market under the names of bin'zliwhcat ricci andbarley but this separation is not always commercially feasible, and evenwhenpracticed, there is always left a largegresidue, consisting of finerparticles of anthracite, carrying a considerable percentage ofash-producing constituents, which residuo, in so far as I ain aware, hasnot heretofoicbeen successfully utilized as a fuel, although itspercentage of combustible matter is sullicient to constitute itavaluable l'uel were it properly and completely burned. Bytlie prac--tice of my invention, it is feasible to burn this euhn, whether with orwithout the preliminary separation therefrom of the smaller sizes ofcoal above specifically referred to,

muy bituminous coal, it' contains comparatively little igniliblehydrocarbon.

ln the practice of -my invention. l first grind the anthracite cnlm in adry condition` to an exceedingly liuc powder, the grinding operationpreferably -rcducing it to such a minute degree of subdivision that say8574- of the mass would pass through a screen of No. 200 mesh. By theuid of an air current of suliicierit pressure, the finely. R. Baiixinuasr. a citizen of the United States, residpnlverized and dili -ultlyignitible culmis injected imo my combustion chamber in the forni of afuel cloud, and under such conditions that tlie cloud-like body as itenters,

the combustion chamber travels in close proximity to a highly heatedignition surface (preferably the lower surface of the arch of thecombustion chamber) where it is ignited. It then returns upon itself inthe form of-o loop, the outgoing branch of the loop radiating its heatupon t-he incoming branch in process of ignition, and preferably takingits exit from the combustion chamber in such manner that the productsof' combustion will enveloo the conduit through which the mixture olithe pulver-ized Patented June 14, 1910.

culm and air is injected. This intersection Y.

of the products of combustion with the oonduit through which the fuelcloud enters tends to correspondingly preheat the latte-r,-

and has the additional function that at. this point a minor portion ofthe products of combustion is entraincd with and joins the incomingbranch of the loop thereby assisting in its deflagration by adding tothe fuel cloud the sensible heat of the combustion products thusentrained... Finali the.

main body ortion of the products o combastion, on caving the combustionchamber traverses the reverse side of the ignition wail or arch abovereferred to, thereby transmitting therethrough Yto the enteringfuelcloud such a large amount of heatlthat, in practice, itis found thate'cctive i nitioii or detla'ration of the fuel and its u tiinatepractically complete combustion'can be relied upon.

ln the accompanying drawing, I have illustrated a form of apparatuswhich T h'avo found well adapted for the practice of my invention, andwhich, in operation, em-

bodies iny preferred plan for carryingit into cll'cct.

ln thc drawing, Figure 1 representen. longitudinal sectional view of insaid p referred forni of apparatus; and fi, 2 represents a.cross-sectional view thcreo taken on a planeindieated bv thc line '2,-2of Fig. 1. Similar letters of reference indicate simi lar parts in bothviews.

Referring to che drawing, A indicates the front outer wail of thefurnace. structure, B the outer side walls thereof, and C thecoinbustion chamber. One of the walls o f the los' l combustion chamber(preferably the arch a' thereof) is made quite thin, say nine inches inthickness or thereabont, and of refractory material conductive to heat.(the more rou'- ductive the better), and is intended to .serve as theignition wall or arch lu-.reiubefore referred to, Accordingly, the pipeb through which theffnixtturel of air and pulrerized eulm is projected,and the surrounding conduit or twyez' l: through which an additionalamount of atmospheric air is drawn in, are located just ont of line withtle inner surface of the wall or arch a, so as to direct the `incomingfuel cloud along and in close prox imity thereto.'

At its furthermost or rear end, thtl combustion chamber C is curved, asshown, and its walls are preferably made smooth throughout so as tominimize -thc formationv Spf interfering eddy currents. The exit port ilfor the products of combustion is located the temperaturevof the latterand thus to asv sist. in continuously maintaining it at thcV fullignition point.

Before injecting. into the combustion chamber the mixture of air andpulrerizcd culm, l heat the combustion chamber to such a degreeand insuch manner as will bring it to the temperature necessary to initiate`the ignition and combustion of the mixture ot' air and pulverizcd culmwhich would otherwise not ignite. While this preliminary heating of thecombustion chamber ma he etlected in various ways, such a`s by ma 'ingtherein a wood tire, I find that it ma he quickly and eourenier-.tlybrought to a iigh temperature by thereafter introducing,-V

throuqh the pipe b, the usual mixture of air and fihcly pulverizcdordinary bituminous coal, which then readily ignites because of thelarge proportion of rich hydrocarbons resent in that fuel. mationchamber has been sufficiently heated, and particularly as soon as theinner surface of the wall or arch a Ahas been raised to thc temperaturenecessary for insuring and:

maintaining ignition of the mixture of air and ulverized cnhn, the snply of )ulverized Eituminous coal is cut o and t e pulverized cuhn issubstituted therefor. The regular operation then proceeds continuously.The mixture of air and pulverized culm projected into the combustionchamber through the pipe b draws in an additional supply of-air throughthe conduit c and'is at;

1n proximity to the entra nce conduit for the l lfuel cloud, and thesaid exit port leads into P As soon as the c-omonce ignited by thc heatradiated upon :'i from the ignition wall or arch n. 'l`hc 'if l nih-dfuel cloud traveling rapidly aloof;- the wall or arch n constitutes theenrwucc of the loop is thus radiated, as the opera! im proceeds. u onthe entering branch of th.`

and ignited fuel cloud o ai arl pulrcri/.cd culm.

A portion of the products` of f'oxuhnstifaom the Home cloud is drawninto the entr-r i 'jg fuel cloud at the point where the latter issuesfrom the injector into the combustion chamber. thereby impartin; r toth.` fue! cloud the sensible heat of thc portion of t'ac products ofcombustion thus 'cntraincd Fuimident with the intense infialning ofthem.'-A turn hond or current of the loop, the aecour have experiencedan enormous erpansiou.v -o that the flame cloud rises through the uptake in strong volume and with a velocity which is greatest at. themiddle of the arch a.

i preferable point of location for the fuel ini jcctor, althoughIitu-ill he understlmd that l do not limitmyself to such location` as insome instances. especially, for large furl naces, it may be fpunddesirable to use more i than one fuel in]cetor. Finally, the main bodyportion of the products of combustion, l issuing and passing along theidc und soaclous tine e on the reverse sido ot' the highly Il conductingthin `wall or arch a ltccps said I wall or arch continuously at the hightcmperaturc newssary for thc maintenaluc of i ignition of the enteringcloud of air and l pnlvcrizcd culm. l'tftersnbservingthc functionsdescribed, the'products of combustion i'pass on to the place of use forwhich they are intended, as, for instance. to a steam iii-Inch of theloop. The ignition prog'wfl-c the flame cloud constitutingvthc returnbend loop consiscang ot` the continuously supplied panying air andproducts of combustion Accordingly l have selected this point as the.

lltl

i boiler, a kiln, the lai-oratory of a metallurl i git-.al or heatingfurnace, or the like. g While I have described in detail the speciticapplication of my invention to the l waste material known' asanthracitel cuhn` l yet, it will be quite evident that the method ldescribed is equally appli 'able to other fuels lof diflicultignitibility which are usually, for this very reason, regarded as wastefuels. and exist at. present, in enormous quant itu-s. Such materialsform at, the present time a large item in the waste of our naturalresources, and their etlicient, utilization is o' ..t 1.1 15mm-..4

cat economic and national importanrv.

mong such materials l would enumerate coke breeze, charcoal breeze. tankmud from coal Washeries` and low grade bituminous dusts of difficultignitihility, containing high percentages of ash. Furthermore. it isquite within the range of practicability to pulverize the smaller .sizesof antl aeite Coal and burn them as dust hy my invent-ion. l wish,therefore. to include artiticiallv powdered anthracite with theanthracite onlin. as within the scope of my invention.

Havingr thus described my invention. what l' claim is:-

1. The method of burningT anthraciteculm and similar materials. whichConsists in raising the temperature of a combustion chatnlie-rv up tothe ignition point of a hotly 'of air mixed with Asuch material inpowdered forni, projecting the mixture into, and along a wall of. theeomhustion chamber and ignitingz it therein. causing the products ofeomf and similar materials, which consist.: in projecting into acombustion chamber and aloruv a wall thereof a body of'air mixed withsuch material in powdered form, preheating said wall up to the ignitiontemperature of said mixture. whereby` as the incoming?Y current.

enters. it will be ignited, causing the. prod` nets. of combustion toreturn upon themselves within the combustion chamber. the return currentradiatinf: heat upon the iiicoming current. entiaining into theinconifeomhustion chamber; substantially as de scribed.

4. The method of burning anthraate euhu and similar materials. whichronsists in rojerting: into a romhustionehamher and a ong,l

r a wall thereof a hotly of air mixed with such and causing the productsof eomhustioiu after takin; their exit from the conduis-'tion elnunla-r.to maintain said wall at an ignition temperature at4 the point ofdischarge g selves within the combustion chamber, the

of tlu fut-l: substantially as doaerilied.

The method of burningr anthraeiteeulm and Similar materials. wlueh'consists in pronuiterial in powdered form. preheating .said wall up tothe ignition temperature of said mixture, whereby as the incomingcurrent enters it will he ignited. causing the products of combustion toreturn upon themreturn current radiating heat upon 'the ini comingcurrent, entrainxng into the incomjevting into a combustion chamber andalongr 5 a highly heated ignition .surface thereof a ,i hotly of airnuxed with such material in I powdered forni. thereby igniting the mix-I ture, causing the product" of combustion to return upon themselveswithin the combustion elsambt-r. iluI return current radiating:

its heat upon une side of the incoming curi rent. and t'nrtlu-r heatingthe incoming.: current so as to asas! in its detlagration hy I musingthe produtts of combustion after they leave the combustion chamber topars along thc reverse side of thc highly heated ignition surface andmaintaining:r said surface tlu-reliy at an ignition temperature at thepoint of discharge of the fuel; 4substantiallj, as described.

3. The method "t burning anthraeitecnlm ing current a portion of theproducts of combustion from the return current. prelieating the incomingmixture of air and fuel powder by heat from thc outgoing products ofconihuslion. and continuousl)l maintaining the preheated wall at thepoint of discharge of the fuel atthe ignition temperature for-iluxmixture b v passing the outgoing produvts of combustion along itsreverse side after they leave the cnnbust ion chamber: substan tially asdescribed.

In testimon whereof I ax my signature. in presence o two witnesses.

HENRY R. BARNlIliltS'l.

Witnesses:

Summer Il. KING. Raynox!) \l I ns'rz.

